1. Field of the Invention
The invention relates to a method for operating an automation system having a memory in which a control program is stored as an automation solution and, more specifically, to a situation such as arises when at the runtime of parts of the control program these parts of the control program have to be replaced with updated parts without the execution of the control program and overall operation of the automation system being noticeably interrupted. Such a replacement of parts of the control program is referred to as delta loading, where such parts of the control program are referred to in the following as software modules.
2. Description of the Related Art
The problems associated with delta loading have been the subject of discussion for a long time. At present, however, only solutions that can be used if no change is made to the interface of the respective software modules are available for automation systems. The reason for this is that such data resides sorted in a sequential manner in a data area assigned to the software module, referred to as the instance (DB). Consequently, if a data area is modified, the address locations of all the succeeding data are shifted. Due to the shifting of the address locations of following data areas, a loaded instance (DB) also cannot be extended without due consideration.
Accordingly, with the conventional solutions that are available, if a change or correction to a software module is made, which can only be accomplished by extending the data in the associated data area (new inputs or outputs or additional data), then at the present time the module can only be loaded into the automation system if the automation system is first transitioned to a stopped state, i.e., if the execution of the control program is interrupted. In an automation system that is in the stopped state there is consequently also an interruption to the control and/or monitoring of the respective technical process for the duration of the stopped state.